First, thanks a lot for this wonderful tool ; I'm using it in Pétrolette, a (beta) RSS reader to sync the feeds between connected clients, using 5apps storage, and it works great.

I made tests with Dropbox and Google drive but I decided I don't want those options at the moment ; Now I was under the impression that it was only a matter of providing or not providing an API key to toggle the corresponding service option / button on / off, but apparently once you provided said key once, there is no way to make those two buttons disappear

It looks like it's a caching issue. You should be able to run localStorage.clear() in your browser's console to get rid of the Dropbox and Google Drive buttons. The current deployed version of http://petrolette.space/ doesn't have Dropbox and Google Drive enabled. You can confirm that with a different browser, or in private mode.

remoteStorage.js will store those keys in localStorage when launching the app. Usually it's simply a matter of clearing that once, e.g. by opening the browser console and doing localStorage.clear().

By the way, a new feeds module would be fantastic! @silverbucket was working on a demo feedreader app called Dogfeed in the past, and planned to update it in the future. So those two apps could interop then.

I think calling it a "caching issue" is not ideal. The keys are coming from cache, but there's no issue with that really. If an app has other backends enabled in production, and then the developer decides to disable those, then they should manage that from code, and ideally give the opportunity to migrate the data or at least have a transition period of time, during which the data is still accessible through the app.

It's an intentional design decision, of which I think the main caveat is when playing around on localhost. I think we should document this better.